The research objective is to define the relationship of the laryngeal chemoreceptors for saline and water to apnea of prematurity and the Sudden Infant Death Syndrome (S.I.D.S.). The role of these laryngeal chemo-receptors for the coordination in respiration and swallowing in order to avoid aspiration will also be explored. The receptors will be identified first in newborn lambs anatomically and functionally through alteration of the receptors and the laryngeal epithelium. The respiratory and swallowing response to various stimuli will be examined to test the hypothesis that there exist two reflexes, both elicited in the laryngeal area; one reacting to solutions which contain little or no saline which elicits swallowing and apnea, the other reacting to saline causing continuation of breathing and little swallowing. If promising results from animal experiments are obtained, studies will be performed on human infants to find ways of influencing this chemosensitivity which may have preventive and therapeutical implications for infants with apnea and SIDS. In accordance with these results it is also possible that the composition of oral feedings can be changed to improve feeding regimens in premature infants. Cardiac output distribution studies will be performed in newborn lambs during the water elicited apnea reflex response to see if intestinal ischemia is found similar to what occurs in the diving reflex. If such a blood flow redistribution is found its association to neonatal Necrotizing Enterocolitis (NEC) will be explored and ways of blocking it will be sought in order to prevent the development of NEC.